Various wireless communication systems are known and understood in the art. Many such systems accommodate the communication needs of mobile users. Many wireless communication systems only provide services within a given zone (or zones) of wireless coverage. As a result, when a mobile user moves from within a zone of wireless coverage to an area without service, a then-present wireless communication will typically be dropped.
System designers have a growing desire to avoid such dropped or interrupted communications. For example, there is present conceptual interest in facilitating a handover of a present wireless communication from a first wireless communication system (such as a wireless local area network) to a second wireless communication system (such as a wireless wide area network).
The basic concept of transferring a present wireless communication from a first wireless base site to another is known. Cellular telephony systems are an example of a wireless wide area network that internally accommodates such functionality. Unfortunately, at least at present, a handover from a first wireless system such as a wireless local area network to a second system such as a wide area network necessarily entails a system-to-system transfer as versus an internal transfer within a given system.
Additional concerns further complicate the matter. A typical wireless local area network (such as, for example, an 802.11-family compatible local area network) will use radio frequency resources, and have an infrastructure, that varies considerably from a typical wireless wide area network (such as, for example, a cellular telephony system). Multi-mode radios have been proposed that are capable of compatibly operating in two (or more) such divergent systems. Such intrinsic compatibility, however, does not necessarily lead to a satisfactory ability to effect a relatively transparent handover of a given wireless communication between such divergent systems.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.